/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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package org.mozilla.intl.chardet;

public class nsEUCSampler {

  public int[] mFirstByteCnt = new int[94];
  public int[] mSecondByteCnt = new int[94];
  public float[] mFirstByteFreq = new float[94];
  public float[] mSecondByteFreq = new float[94];
  int mTotal = 0;
  int mThreshold = 200;
  int mState = 0;

  public nsEUCSampler() {
    Reset();
  }

  public void Reset() {
    mTotal = 0;
    mState = 0;
    for (int i = 0; i < 94; i++) {
      mFirstByteCnt[i] = mSecondByteCnt[i] = 0;
    }
  }

  boolean EnoughData() {
    return mTotal > mThreshold;
  }

  boolean GetSomeData() {
    return mTotal > 1;
  }

  boolean Sample(byte[] aIn, int aLen) {

    if (mState == 1) {
      return false;
    }

    int p = 0;

    // if(aLen + mTotal > 0x80000000)
    //    aLen = 0x80000000 - mTotal;

    int i;
    for (i = 0; (i < aLen) && (1 != mState); i++, p++) {
      switch (mState) {
        case 0:
          if ((aIn[p] & 0x0080) != 0) {
            if ((0xff == (0xff & aIn[p])) || (0xa1 > (0xff & aIn[p]))) {
              mState = 1;
            } else {
              mTotal++;
              mFirstByteCnt[(0xff & aIn[p]) - 0xa1]++;
              mState = 2;
            }
          }
          break;
        case 1:
          break;
        case 2:
          if ((aIn[p] & 0x0080) != 0) {
            if ((0xff == (0xff & aIn[p]))
                || (0xa1 > (0xff & aIn[p]))) {
              mState = 1;
            } else {
              mTotal++;
              mSecondByteCnt[(0xff & aIn[p]) - 0xa1]++;
              mState = 0;
            }
          } else {
            mState = 1;
          }
          break;
        default:
          mState = 1;
      }
    }
    return (1 != mState);
  }


  void CalFreq() {
    for (int i = 0; i < 94; i++) {
      mFirstByteFreq[i] = (float) mFirstByteCnt[i] / (float) mTotal;
      mSecondByteFreq[i] = (float) mSecondByteCnt[i] / (float) mTotal;
    }
  }

  float GetScore(float[] aFirstByteFreq, float aFirstByteWeight,
                 float[] aSecondByteFreq, float aSecondByteWeight) {
    return aFirstByteWeight * GetScore(aFirstByteFreq, mFirstByteFreq) +
        aSecondByteWeight * GetScore(aSecondByteFreq, mSecondByteFreq);
  }

  float GetScore(float[] array1, float[] array2) {
    float s;
    float sum = 0.0f;

    for (int i = 0; i < 94; i++) {
      s = array1[i] - array2[i];
      sum += s * s;
    }
    return (float) Math.sqrt((double) sum) / 94.0f;
  }
}


